Method for converting a gas comprising carbon monoxide into methane by means of a catalytic material containing praseodymium and nickel on alumina

Abstract

The invention relates to a method for converting a gas into methane (CH4) which includes:a step of activating a catalytic material including praseodymium oxide (Pr6O11) associated with nickel oxide (NiO) and alumina (Al2O3), the respective proportions of which are, relative to the total mass of these three compounds:Pr6O11: 1 wt % to 20 wt %,NiO: 1 wt % to 20 wt %, andAl2O3: 60 to 98 wt %; anda step of passing a gas including at least one carbon monoxide (CO) over the activated catalytic material.

The invention claimed is: 
     
       1. A device for converting carbon monoxide (CO) into methane (CH 4 ), which comprises:
 a reaction area, comprising a fluidized bed comprising a catalytic layer having a specific surface area (SStel) between 100 and 250 m 2 /g, the catalytic layer being obtained by activating a catalytic material by heat treating the catalytic material in the presence of reducing agents at a temperature in the range of 300-500° C., the catalytic material including praseodymium oxide (Pr 6 O 11 ) associated with nickel oxide (NiO) and alumina (Al 2 O 3 ), the respective proportions of which being, in the catalytic material, relative to the total mass of these three compounds:
 Pr 6 O 11 : 1 wt % to 20 wt %, 
 NiO: 1 wt % to 20 wt %, and 
 Al 2 O 3 : 60 wt % to 98 wt %; 
 
 an inlet for passing an incoming gas including at least carbon monoxide (CO) over the catalytic layer in the reaction area, 
 an outlet for releasing a product gas passed over the catalytic layer and including at least methane resulting from a catalytic reaction of the incoming gas passed over the catalytic layer in the reaction area; and 
 heat exchange tubes disposed in said reaction area and being configured to maintain temperature of said reaction area and in said outlet below 300° C. 
 
     
     
       2. The device according to  claim 1 , wherein said heat exchange tubes are immersed in the catalytic layer. 
     
     
       3. The device according to  claim 1 , wherein said device is configured to maintain temperature of said catalytic layer below 300° C. during the conversion of the carbon monoxide (CO) into methane. 
     
     
       4. The device according to  claim 1 , wherein the catalytic material presents a bead shape with a mean size of between 100 and 1000 μm. 
     
     
       5. The device according to  claim 1 , wherein the catalytic layer is obtained by activating the catalytic material, and wherein said respective proportions are:
 Pr 6 O 11 : 3 wt % to 15 wt %, 
 NiO: 3 wt % to 15 wt %, and 
 Al 2 O 3 : 70 wt % to 94 wt %. 
 
     
     
       6. The device according to  claim 1 , wherein the alumina has a mesoporosity corresponding to a median diameter of the pores, determined by Hg intrusion porosimetry, of between 3 and 50 nm. 
     
     
       7. The device according to  claim 1 , wherein the alumina (Al 2 O 3 ) has a gamma structure. 
     
     
       8. The device according to  claim 1 , which further comprises a catalytic material preparation unit. 
     
     
       9. The device according to  claim 1 , which further comprises, before the inlet, a unit for constituting the incoming gas, comprising at least one of:
 a pyrolysis unit for hydrocarbon materials; 
 a pyro-gasification unit for hydrocarbon materials; 
 a gasification unit for hydrocarbon materials; 
 a CO 2 /H 2 O co-electrolysis unit; 
 a water-Gas-Shift unit; and 
 a reverse Water-Gas-Shift unit. 
 
     
     
       10. The device according to  claim 1 , wherein the inlet and outlet are positioned on either side of the catalytic layer, and the product gas is passed through the catalytic layer. 
     
     
       11. The device according to  claim 1 , wherein the inlet and outlet are positioned on either side of the catalytic layer, and the product gas is passed over the catalytic layer. 
     
     
       12. The device according to  claim 1 , which further comprises a unit for conducting the heat treating of the catalytic material to obtain the catalytic layer.